Apparatus for grading objects such as fish

ABSTRACT

A grading apparatus, especially for delicate material such as fish. The apparatus consists of a feeding device, ridged belts, rail guides for the transport and grading of material, grading compartments, a driving device and adjustment mechanism. The material to be graded is fed to the feeding device and therefrom onto the ridged belts, which transport it and grade it by thickness into the appropriate grading compartments. The apparatus is unique in that the feed device ( 4 ) consists of one or more interconnected and adjustable stages ( 4   a   , 4   b   , 4   c ). Each stage is equipped with side panels ( 67 ) or/and turning pins ( 55 ), side panels ( 67 ) dividing each stage into one or more channels ( 70 ) through which the objects are transported to thereby control the flow direction ( 77 ) and the velocity of the objects at each stage and onto the ridged belts ( 3 ).

TECHNICAL FIELD

The invention concerns an apparatus for grading objects, such as fish,comprising feeding means, ridged belts, rail guides, gradingcompartments, driving means and adjustment mechanism. The objects arefed onto the feeding means and therefrom onto the ridged belts. Theridged belts being build of numerous units of triangular cross-sectionfastend to each other in continuous bands. The bands being pulled overthe rail guides which determines the distance between the ridged beltsso that their distance is greater at the out-feed-end than at thein-feed-end.

BACKGROUND OF THE INVENTION

The grading of objects such as fish and marine species such as capilionand herring can be a problem. The reason being their small size and thevolume to be processed at each time combined with that the quality offish deteriorates quickly if not stored at sub zero temperature. Thegrading therefore has to be highly efficiently The purpose of thegrading is primarily to separate the species by size and/or the sex.Such grading can often result in substantial increases in value asfemale capilion filled with eggs is much more valuable than the malespecies. No feasible methods are currently known for such grading.

There are machines, which are capable of grading fish and other objectsby size, especially thickness. These include belt and roller machines ofvarious types and shaker graders. The best known, are belt machines,which pull the object between two slanting belts which form a transportchannel. These machines frequently have many channels. There are alsoroller machines where two or more parallel rollers form lanes slantingin the direction of movement of the object. The rollers rotates and theobject moves forward. The distance between the rollers is greater at theoutput end than the input end so that the smallest units of objects arefirst to fall between the rollers while the larger units fall later. Inthis way, grading by thickness corresponds to increased distance betweenthe transport belts or rollers. This applies generally to machines basedon designs where the distance between lanes is greater at the out-feedend than the in-feed end.

Numerous patents are known which in one way or another attempt to solvethis complex problem. U.S. Pat. No. 1,373,812 from 1921, is known whichdescribes a spinning feeding mechanism for grading of sardines. U.S.Pat. No. 2,314,479 from 1943, is known which concerns grading of fish bysize and its handling during processing. Norwegian patent, No. 132.917from 1974, is known which concerns transport and grading, especially ofshrimp. British patent, No. 2.140.712A from 1983, is known whichconcerns grading of plums. PCT patent application No. WO 88/06495 from1988 is known, which concerns grading of shrimp and related materials.U.S. Pat. No. 4,723,660 from 1988 concerns apparatus for transport andgrading of material. U.S. Pat. No. 2,547,473 from 1951 is knownconcerning grading of fruit by size. Another U.S. Pat. No. 1,251,093from 1917 concerns grading of fruit and vegetables. Another U.S. Pat.No. 1,204,685 is known concerning grading of fruit and a packagingbench. Another U.S. Pat. No. 1,178,006 concerns grading of fruit andvegetables. Finally, PCT application from the present applicant from1996 concerns a method and apparatus for grading of fish and othermaterials by size.

DISADVANTAGES OF PRIOR ART

Because of the quantity of material to be processed at each time, as inthe case for capilion processing, steady feeding to the gradingapparatus has been a problem. The main problem has been to arrange thematerial into a single layer in optimal position onto the gradingapparatus. If this is not accomplished, small fish may be carried on topof a larger fish into a wrong grading compartment. The advantages ofusing ridged belts against grading by weight have not been fullyutilised. Various species of fish have characteristic features. The malecapilion, for instance, has during the egg-laying season hair-brushes onits sides. The eyes of certain types of red-fish props out when takenfrom large sea depth and high pressure, to mention some of thecharacteristics that can be used for grading by criteria other thanweight. By utilising these characteristics of the species concernedtheir grading can be simplified and thereby their value increasedsubstantially. None of the patents referred to above ad dress thesecharacteristic features or show how they can be used.

SUMMARY OF THE INVENTION

The purpose of the invention is to present apparatus for grading ofmaterial, especially delicate material such as fish. The apparatusconsists of a feeding mechanism, ridged belt and rail guides for thetransport and grading of material, grading compartments, drive mechanismand adjustment mechanism. The material to be graded is fed into thefeeding mechanism so that the material can be fed into the ridged beltsin the optimum position and at the same speed as the transport speed ofthe ridged belts, which transport it and grade it by thickness into theappropriate grading compartments. The ridged belts are composed ofnumerous units with a triangular cross-section and connected into acontinuous band which is pulled over the rail guides. The orientation ofthe rail guides, and thereby the ridged belts, is determined so that thedistance between them is greater at the outer end than at the inner end.In addition, the ridged belts can be used to grade material withspecific features or shape which can be utilised in addition to thethickness grading.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention can be described in greater detail by referring to theattached drawings where:

FIG. 1 shows a lateral view of the grading apparatus,

FIG. 2 shows a top view of the grading apparatus,

FIG. 3 shows the details of the ridged belts,

FIG. 4 shows the details of the feeding chute,

FIG. 5 shows a lateral view of an alternative version of the ridgedbelts,

FIG. 6 is a cross-sectional view taken along the line 6—6 of FIG. 5 andshowing the design of the ridged belts,

FIGS. 7(a), (b), and (c) show the placement of the turning pins in thefeeding apparatus, and

FIG. 8 shows yet a further version of the arrangement of the ridgedbelts with gradually increasing distance between them.

DESCRIPTION OF THE INVENTION IN GREATER DETAIL

The purpose of the invention is attained by the apparatus's uniquefeatures in that the feeding means, comprising one or moreinterconnected and adjustable stage, each stage being equipped withguiding plates or/and turning pins, the guiding plates dividing eachstage into one or more channel through which the objects are transportedand thereby controlling t he flow direction and the velocity of theobjects at each stage and onto the rigid belts, which transport andgrades the objects according to thickness into the appropriate gradingcompartments.

The apparatus is also unique in that the guides or guiding plates areperpendicular to the bottom area of individual feeding stages andparallel to the flow direction of the material. The number of guidingplates is smallest in the in-feed stage and greatest in the out-feedstage.

Furthermore, the inclination of the feeding stages is adjusted so thatthe flow rate of the objects in the out-feed stage is substantially thesame as the velocity of the ridged belts. The inclination of individualfeeding stages is so adjusted that the objects are fed onto the rigidbelts in nearly single layer in an optimal position.

In addition, the turning pins extending from the lower edge of thefeeding stages and curved upwards to form up to 90° angle to the bottomarea of the feeding stages. The maximum number of turning pins is equalto the number of ridged belts. Further the turning pins are positionedeither at the bottom or top of the furrows.

In addition the rigid belts are equipped with guiding plates which arepositioned above and parallel to the rigid belts. Also the distancebetween the ridged belts is adjusted so that it increases approximatelyby an elliptical curve from the out-feed end to the in-feed end of theridged belts. Moreover the panel sides of the ridged-belt units featureelevated furrows extending approximately perpendicular to the directionof movement of the ridged belts. Also the ridged belts are upwardlyinclined in the direction of movement of the belt.

Moreover the inclination of the ridged belts is approximately −3° to 25in the direction of movement. At last the slant of the ridged belts isapproximately 4-8°, more specifically 5-7° in the direction of movement.

FIG. 1 shows a lateral view of the grading apparatus. FIG. 2 shows a topview of the same apparatus. The material to be graded is transported tothe apparatus, e.g., with a conveyor belt (74) as shown on theillustration. From the conveyor belt it falls down to the first feedingstage (4 c) of the feeding apparatus (4). The illustration shows threefeeding stages (4 c, 4 b, 4 a) each following the other. There can bemore or fewer stages. The slant (76) of the stages can vary and isadjustable for each stage. The stages are adjusted and supported by aspecial framework (56, 58, 59, 60). The framework can standindependently of the supporting framework (1) of the grading machineitself. When the material falls off the final stage it falls down to theridged belts (3) of the grading apparatus. The ridged belts (3) arepulled by a drum-shaped driving mechanism (6,7) at either end of theapparatus. At the front end (the in-feed end) of the apparatus there isa special stacking mechanism consisting of vertical guiding plates (64)extending above and parallel to the top edges of the ridged belts. Thepurpose of the stacking mechanism is to ensure still further thearrangement of the material into a single layer onto the ridged belts.In order to improve the grading, it is possible to tilt the ridged beltsby −5° to +25° depending on the material being graded.

FIG. 3 shows the arrangement of the ridged belts (3). The ridged belts(3) are seated and slide in the so-called ridged-belt rail guides (2).The aspect of the ridged belts (3) and rail guides (2) are determined bythe orientation of the adjustment pins (12) and the adjustment bar (9).The adjustment bar extends across the apparatus, and three such barssupport the ridged-belt guides and the ridged belts. Each bar (9) isfitted with up to four rows of adjustment pins (12). Each row ofadjustment pins has a predetermined distance between individual pins. Byturning the bar (9) by 90° and attaching a new row of adjustment pins tothe ridge-band guides the distance (42) between the ridge bands (3) canbe increased.

FIG. 4 shows one version of the feeding mechanism. Three stages, 4 a, 4b, and 4 c, are shown. The highest stage has two side panels (67) whichform a single chute. The next stage has 5 side panels (67′) that form 4chutes (70). The lowest stage (4 a) has 7 side panels (67″) which form 6chutes. The stages can be slanted in different directions depending onthe material being graded. When a fish lying across the direction ofmovement falls from the first stage (4 c) and lands on the panels (67′)of the second stage (4 b), the heavier end will seek to enter the chutefirst and the fish will be turned. This is repeated between stages twoand three so that a fish emerging from the last stage will always facethe correct direction. From the smooth surface of the top stage (75)which may be wetted by sprinkling with water, the material will slide tothe next stage. The side panels form box-like chutes or channels (70).Their width is somewhat less than the length of the material, whichenforces turning of the material so that its longer axis will turn inthe same direction as the direction of motion of the belts. The numberof stages may be increased as well as the number of panels thusnarrowing each chute (70).

FIGS. 5 and 6 show an alternative version of the ridged belts (3). Theside panels (71) are partly raised. The smooth side panel is coveredwith a waved pattern.

This makes it possible to, grade material by thickness even if someparts of the material protrude. This applies e.g., red-fish, which hasextremely protruding eyes when it emerges from the fishing gear offishing vessels. This feature makes it possible to grade red-fish bythickness (size) without the grading being affected by the protrudingeyes. The eyes fit into the gaps between the waves (72) while the bodyof the fish is flush with the waves (72). Thus, it is in fact thedistance (42) between the tops of the ridges parallel to the ridgedbelts which determines the grading.

FIG. 7(a) shows the feeding stages (4) with turning pins (55) at theouter end of the feeding stages. The stages in this version as shown inFIG. 7(b) have a corrugated bottom. The turning pins (55) are either atthe top (62) of each corrugation as shown in FIGS. 7(b) and (c) or atthe bottom. When a fish lands across the direction of movement and landson the pins, it is turned and is aligned correctly in one of thecorrugations of the next stage.

FIG. 8 shows another version of the ridged belts where the distance (42)between two adjacent ridged belts (3) increases in an elliptical curveso that the distance is much greater at the outer end (69) than theinner end (68). By using three supporting bars (9) as shown in FIG. 3,the adjustment options of the grading slit are increased. With thecorrect distribution of each support bar, the direction of the railguide can be curved so that the initial part of the grading slit can benarrow with increasing distance for each unit of length.

The invention described here above is not limited to precisely thosedetails which have been specified, but can be elaborated upon in manyways without deviating from the central concept and spirit of theinvention as defined in the patent claims below.

What is claimed is:
 1. In an apparatus for grading objects havingfeeding means, ridged belts, rail guides, grading compartments, anddriving means, where the objects are fed onto the feeding means and fromthere onto the ridged belts, the ridged belts being formed from numerousunits of triangular cross-section fastened to each other in continuousbelts, the belts being pulled by the driving means over the rail guideswhich determines the distance between the ridged belts so that thedistance is greater at an out-feed end than at an in-feed end of theridged belts, the improvement wherein the feeding means comprises aplurality of interconnected and adjustable feeding stages, each stagebeing equipped with side panels that divide each stage into one or morechannels through which the objects are transported to thereby controlthe direction of flow of the objects and the velocity of the objects ateach stage and onto the ridged belts which transport and grade theobjects according to thickness into appropriate grading compartments,wherein said side panels are perpendicular to a bottom area of eachindividual feeding stage and parallel to the direction of flow of theobjects and the number of side panels is the smallest at an in-feedstage at an in-feed end of the feeding means and greatest at an out-feedstage at an out-feed end of the feeding means, and wherein sides of theridged-belt units have elevated waves extending approximatelyperpendicular to a direction of movement of the ridged belts from thein-feed end to the out-feed end thereof.
 2. The apparatus of claim 1,wherein the feeding stages are inclined and the inclination of thefeeding stages is adjusted so that the velocity of the objects at theout-feed stage is substantially the same as the velocity of the ridgedbelts.
 3. The apparatus of claim 1, wherein the feeding stages areinclined and the inclination of individual feeding stages is adjusted sothat the objects are fed onto the ridged belts in nearly a single layer.4. The apparatus of claim 1, including turning pins extending from alower edge of each of the feeding stages that curve upwards to form a90° angle with respect to the bottom area of the feeding stages.
 5. Theapparatus of claim 1, including guiding plates positioned above andparallel to the ridged belts at the in-feed end of the ridged belts. 6.The apparatus of claim 1, wherein the distance between the ridged beltsis adjustable so that the distance increases approximately by anelliptical curve from the in-feed end to the out-feed end of the ridgedbelts.
 7. The apparatus of claim 1, wherein the ridged belts inclineupwardly in a direction of movement of the ridged belts from the in-feedend to the out-feed end thereof.
 8. The apparatus of claim 7, whereininclination of the ridged belts is approximately −3 to 25° in thedirection of movement relative to a horizontal plane.
 9. The apparatusof claim 8, wherein the inclination of the ridged belts is approximately4-80.
 10. The apparatus of claim 9, wherein the inclination of theridged belts is from 5-70.
 11. The apparatus of claim 4, wherein themaximum number of turning pins is equal to the number of ridged belts.12. The apparatus of claim 4, wherein the bottom areas of the feedingstages are corrugated and the turning pins are positioned either at abottom or top of each corrugation.